Browsing by Author "Dr. Ishrat Sultana"

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3D-printing of metallic nanoparticles via electrodeposition on paper based electrodes for energy storage application
(Library Information Services, COMSATS University Islamabad, Lahore Campus, 2023) Ammara Kanwal; CIIT/SP22-RPH-006/LHR; Dr. Ishrat Sultana
A fresh method for handling the content develop variety of applications is provided by the ability of three-dimensional (3D) printing technology. Anisotropic in nature, molybdenum disulfide (MoS2) is a multilayer transition metal dichalcogenide (TMD). Its exceptional physio-chemical characteristics include a high carrier mobility, tunable band gap, large surface-to-volume ratio, unique electrical characteristic, friction, catalytic, and optical qualities. However, LC/MoS2 composites are synthesized by microwave assisted method. LC/MoS2 nanosheets electrodeposited by silver (Ag) and gold (Au) to enhance the electrical conductivity of LC/MoS2 substrate. The characterization performed for the properties of this composites include electrochemical analysis, FESEM, Raman & UV- vis spectroscopies. As a result, current density of 2 A g−1, the nanocomposite exhibits an impressive capacitive response of capacitance 9.1 F g−1. Absorption peak lies in the visible region with band gap of 1.9 eV. In summary, we have effectively combined the optical and electrical properties of the different components to create a unique composite that served as a useful platform for the advancement in energy storage applications.
Al Doped ZnO Nanomaterial For Solar Cell Application
(Library Information Services, COMSATS University Islamabad, Lahore Campus, 2025) Attiya Afzal; CIIT/SP21-RPH-027/LHR; Dr. Ishrat Sultana; LHR TP 9998
The energy problem is the most fascinating problem in this world because the way of success of every country is depending upon the development of low cast, well-ordered and high efficiency energy source devices. There are several research groups are working to develop the devices for renewable energy sources. So, we are going to focus our research on solar cells materials for renewable energy source like Zinc Oxide (ZnO). This material is highly useful for making the heterojunction solar cell as well as window layer. Other hand ZnO is used for 3rd generation/DSSC. In this direction we have synthesized zinc oxide (ZnO) nanoparticles by low- cost co-precipitation method without any surfactants. The synthesized ZnO nanoparticles have done the characterizations like X-Ray Diffraction (XRD), Scanning Electron Microscope (SEM), Energy Dispersive X-ray Spectroscopy (EDS) to evaluate shape, size, reproducibility and morphology of nanoparticles.
Development of Biochar Based Metal Oxide and Metal Sulfide for Their Applications in DSSCs
(Library Information Services, COMSATS University Islamabad, Lahore Campus, 2025) Hasaan Mahmood; CIIT/FA23-RPH-019/LHR; Dr. Ishrat Sultana; LHR TP 9850
Dye-Sensitized Solar Cells (DSSCs) emerge as a promising alternative to traditional silicon-based solar technologies due to their low cost, simple fabrication, and environmental friendliness. However, their performance is often limited by poor charge transport and recombination losses. To address these issues, this research focuses on developing a biochar-based composite using tin oxide (SnO₂) and tin sulfide (SnS₂) for application in DSSCs. SnO₂ was chosen for its excellent electron transport capabilities and chemical stability, while SnS₂, with its narrow bandgap, contributed to efficient light absorption. Biochar, derived from biomass, was incorporated into the system to enhance electrical conductivity, provide a high surface area for dye loading, and serve as a cost- effective and sustainable alternative to synthetic conductive materials. The combination of biochar with SnO₂ and SnS₂ resulted in a composite that improved charge separation and reduced electron recombination, leading to better overall device performance. Detailed structural and optical characterizations were performed to confirm the successful formation of the composite and its desirable properties. Electrochemical analyses demonstrated improved charge transfer behavior and lower internal resistance within the cell. The modified DSSCs showed a noticeable increase in power conversion efficiency compared to conventional configurations. This study not only presents a novel material approach for enhancing DSSC performance but also supports the use of eco-friendly and affordable components in solar energy applications, paving the way for more sustainable photovoltaic technologies in the future.
Electrodeposition of Au/Ni Layers on Tin Sulfide based Energy Storage Paper Electrodes for Improvement of Electrically Conductive Properties
(Library Information Services, COMSATS University Islamabad, Lahore Campus, 2020) Hina Urooj; CIIT/SP18-RPH-007/LHR; Dr. Ishrat Sultana; LHR TP 6071
This research seek to have an unconventional and alternative source for bendable and flexible energy storage devices, which has proved useful to meet the demand of today’s energy crises. It is very beneficial to use natural self-growing plant’s lignocelluloses, which are very sufficient on earth and convert them in the form of paper-based electrodes. In this research, Lignocelluloses were obtain from natural source Monochoria vaginalis (MV). Six samples were prepared for electrodes of energy storage applications. LC/SnS2/Au, LC/SnS2/Ni using single layer electrodeposition technique. Before using these samples in energy storage devices as an electrode material we characterized These for Electrodeposition, Scanning Electron Microscope. Electrodeposition of Metallic layers are deposited on LC/SnS2 sheet by using three electrode setups. The SEM analysis displayed the fine fiber structure engage with each other displaying high mechanical properties with powerful electrodeposited layers of Au and Ni. In these samples nanoparticles of nickel and gold are clearly visible with uniform electrodeposition.
Extraction of Activated Carbon from Biomass for Energy Storage Applications
(Library Information Services, COMSATS University Islamabad, Lahore Campus, 2022) Farzana Bashir; CIIT/FA20-RPH-045/LHR; Dr. Ishrat Sultana; LHR TP 8001
The current energy crisis is at its peak, and traditional energy sources are inadequate to supply modern energy demand. Consequently, the energy storage technology that can sustain current requirements is in high demand. Batteries and supercapacitor are examples of electrochemical energy storage devices (EESDs) that have been developed for a long time as crucial force sources in our daily lives. Orange peel, banana peel, wheat straw, olive stone, pistachio shells, walnut shells, beech wood, and hard coal, among other waste biomass sources, are used to produce activated carbon (AC). Activated carbon is used in energy storage applications due to high electrolyte wettability, high reactivity, and high thermal stability. Non- porous carbons are generated by the environmentally friendly, cheap, and low-temperature method of hydrothermal carbonization. For un-activated carbon we take 20 g of corn hair fiber and make gel in 100 ml DI water material was placed in autoclave at 250 ºC for 16 h. Activated carbon and KOH was taken by the ratio of 1:4 respectively, then grinding it in mortar and pestle, heated at 700-800 ºC at the 3 ºC min-1 ramp in a horizontal furnace under a nitrogen flow environment and held at this temperature for 1h. Hydrothermal process and temperature pyrolysis results in increased content of carbon and its aromatic nature in activated carbon. The percent yield of Activated carbon obtained through this method is much higher than other methods. Raman spectroscopy and Fourier transform infrared spectroscopy were used to evaluate the sample and approximate its composition. Cyclic voltammetry and electrochemical impedance spectroscopy were used to explore the sample's electrochemical properties. CV and Specific capacitance show the enhancement of conductivity. The material has the highest specific capacitance 235 Fg-1.
Fabrication and Characterization of High Surface Area/Nanostructured Metal Based Composites for Energy Storage Applications
(Library Information Services, COMSATS University Islamabad, Lahore Campus, 2020) Muhammad Ahmar Chohan; CIIT/SP18-RPH-006 /LHR; Dr. Ishrat Sultana; LHR TP 6070
Novelty in energy storage and energy conversion devices have been received subjected of great interest as an alternative energy source in nanoscience and nanotechnology. Nanostructure materials have a lot of potential in energy storages application due to their dimensions which plays a vital rule in defining the properties of nonmaterial. We have many materials for energy storage applications, amongst many of the materials manganese dioxide (MnO2) is very suitable medium for supercapacitors and electrodes. In this thesis we have fabricated MnO2 nanostructure as an electrode material for energy storage and energy conversion devices by employed Microwave Assisted Method with freedom of template fee synthesis. Amongst many of the metal oxides, MnO2 exhibit a lot of interesting characteristics, for instance inexpensive, eco-friendly, and a high specific capacitance (1370 F g−1), propose it as the most favorable electrode medium for supercapacitors. Presented thesis is an attempt to enhance the specific capacitance and high surface area of MnO2 composites for their potential applications as energy storage devices.
Fabrication and synthesis of Graphene Based Material through Microwave Assisted Method
(Library Information Services, COMSATS University Islamabad, Lahore Campus, 2021) IHSAN ABBAS; CIIT/ SP19-RPH-013/LHR; Dr. Ishrat Sultana; LHR TP 7235
Graphene nanoparticles have been used at industrial level, coating and drug delivery. Due to quick response time it is used for solar panels. Presently, energy dearth around the globe arises as a paramount subject to be solved. The rapid demand of energy consumption leads the research direction towards development of highly functional energy devices along with ease of utility. Also the choice of high efficiency materials becomes a crucial counterpart analogue to other factors of device fabrication in energy applications. Modern industries are striving to achieve highly effective, in this study, Graphene sheets were prepared by microwave assisted method with variation in stirring time. The prepared material was characterized by XRD, SEM, Raman and CV.
Fabrication and synthesis of Graphene Based Material through Microwave Assisted Method
(Library Information Services, COMSATS University Islamabad, Lahore Campus, 2021) Ihsan Abbas; SP19-RPH -013; Dr. Ishrat Sultana; LHR TP 7235
Graphene nanoparticles have been used at industrial level, coating and drug delivery. Due to quick response time it is used for solar panels. Presently, energy dearth around the globe arises as a paramount subject to be solved. The rapid demand of energy consumption leads the research direction towards development of highly functional energy devices along with ease of utility. Also the choice of high efficiency materials becomes a crucial counterpart analogue to other factors of device fabrication in energy applications. Modern industries are striving to achieve highly effective, in this study, Graphene sheets were prepared by microwave assisted method with variation in stirring time. The prepared material was characterized by XRD, SEM, Raman and CV.
Fabrication of Green Template Based Flexible Electrodes for Hybrid Supercapacitors
(Library Information Services, COMSATS University Islamabad, Lahore Campus, 2022) Asifa Iqbal; CIIT/FA20-RPH-030/LHR; LHR TP 7988; Dr. Ishrat Sultana
For rapid charging transfer and ion transport, multichannel-porous carbon generated from wood can act as a conductive substrate, supporting the high-theory capacitance of pseudocapacitive materials. High-performance supercapacitor electrode materials for NiCo2S4 nanosheets that are hierarchically porous and anchored on the surface of carbonized wood were proposed. The NiCo2S4 nanosheet accumulation was successfully reduced, and the hybrid wood-derived porous carbon-NiCo2S4 nanosheet material (NCS-CW) electrode displayed an 821 F g-1 specific capacity. We believe NCS-CW will be used as an electrode material that holds a lot of potential for energy storage devices because of its excellent electrochemical performance.
Fabrication of Metal Oxide Based Charge Transport Layer for Energy Conversion Devices
(Library Information Services, COMSATS University Islamabad, Lahore Campus, 2025) Kainat Ishtiaq; CIIT/SP24-RPH-011/LHR; Dr. Ishrat Sultana; LHR TP 10123
Energy conversion devices such as perovskite solar cells, dye-sensitized solar cells, and electrochemical energy storage systems have gained significant attention due to their potential to provide efficient, low-cost, and sustainable alternatives to conventional energy technologies. A critical factor influencing the performance of these devices is the charge transport layer, which governs charge extraction, transport, and recombination processes at the interfaces. In this study, nickel oxide (NiO) and zinc oxide (ZnO) were synthesized and investigated as hole transport and electron transport materials, respectively, along with their LC sheet–based composite counterparts, for application in energy conversion and storage devices. NiO and ZnO nanoparticles were successfully synthesized using a simple and cost-effective coprecipitation method, while LC sheet–based composites were developed using corn fiber as a sustainable carbon source to enhance electrical conductivity and interfacial contact. The structural, electrochemical, and vibrational properties of the prepared materials were systematically characterized using cyclic voltammetry (CV), electrochemical impedance spectroscopy (EIS), and Raman spectroscopy. CV analysis revealed that pristine NiO and ZnO exhibited pseudocapacitive behavior due to reversible redox reactions, whereas LC sheet–based composites showed predominantly capacitive behavior with improved rate capability, reversibility, and charge–discharge performance. The enhanced electrochemical performance of the composites is attributed to the conductive carbon network provided by the LC sheet, which facilitates rapid electron transport and efficient ion diffusion.
Facile Synthesis of ZnS Paper Based Composites by Electrodeposition of Metallic Layers for their Applications in Energy Storage Devices
(Library Information Services, COMSATS University Islamabad, Lahore Campus, 2021) Asad Iqbal; SP19-RPH-015; Dr. Ishrat Sultana; LHR TP 7276
Zinc Sulphide nanoparticles have been used in energy storage devices like electronics, batteries and hybrid automobile systems. Recently paper based materials are popular due to their flexibility. Lignocelluloses were extracted from Papaya plants that were grown naturally in this study. Six electrode samples for energy storage applications were produced. Single layer electrode position technique was used for LC/ZnS/Au and LC/ZnS/Ni. In this research study, ZnS nanoparticles were prepared by microwave assisted method with variation in stirring time. The prepared material was characterized by XRD, SEM, Raman spectroscopy,UV and CV.
Impedance Spectroscopy of Metal Oxides and Natural Fiber-Based Paper Electrodes for Potential Applications in Supercapacitors and Batteries
(Library Information Services, COMSATS University Islamabad, Lahore Campus, 2020) Muhammad Sajjad; CIIT/SP18-RPH-009/LHR; Dr. Ishrat Sultana; LHR TP 6072
With this thesis finished all is in place for me to graduate, and thus I would like use the occasion to briefly thank some of the people who have helped me to reach this point. All praise and thanks are due to ALMIGHTY ALLAH, WHO in his infinite mercy and Grace gave me the opportunity to pursue my study on “Impedance Spectroscopy of Metal Oxides and Natural Fiber-Based Paper Electrodes for Potential Applications in Supercapacitors and Batteries”. Glory and Praise to our last prophet HAZARAT MUHAMMAD (Peace Be Upon Him), WHO is forever a symbol of direction and knowledge for whole humanity. First of all I would like to thank my thesis advisor Dr. Ishrat Sultana. It has been great working with her in the final year of the M.phil program in Department of Physics (COMSATS University, Lahore campus), and I have learned a lot from her. I am still amazed by the knowledge that he possesses from all different areas of Physics. I thanked her for all of his patience and guidance. Moreover I am very grateful to my co supervisor Dr. Muhammad Naveed-ul-Haq and Dr. Aamir Razaq for their mentorship and the invaluable advice on academic life in general that he has given me. For someone like me, who is just about to enter the academic world, such insightful perspectives can be more valuable than any knowledge found in books or heard in lectures. I would also like to convey my deepest appreciation to my parents and to my brothers. For making me who I am and frequently reminding me of what truly is valuable in life. With their endless support and encouragement, I have been able to achieve so much more than possibly thought. Finally, I would like to extend my appreciation to all lecturers of M.Phil and to all my friends who have been very helpful throughout my study here.
Investigation on the Magnesium Fluoride as an Electron Carrier Selective Contact layer for Solar Cell Applications
(Library Information Services, COMSATS University Islamabad, Lahore Campus, 2021) Muhammad Zahid Seyal; CIIT/SP20-RPH-048/LHR; Dr. Ishrat Sultana; LHR TP 7696
In this work, Magnesium Fluoride (MgF2) nanomaterials were synthesized by the microwave assisted method. Due to its high transparency, small refractive index and wide band gap would easily replace the amorphous silicon layer (a-Si:H(n)) in silicon heterojunction solar cells. Magnesium nitrate and ammonium fluoride was used for the synthesis of MgF2 nanomaterials. Optical absorptance spectra of the MgF2 films was measured by UV-Vis spectrophotometer. X- ray diffraction (XRD) and scanning electron microscopic (SEM) analysis were performed to characterize the structural and surface morphology of MgF2 nanomaterials. The Fourier transform infrared spectroscopic (FTIR) analysis was used to study the functional groups in MgF2 nanomaterials. Simulation study for the electron carrier selective contact solar cell device was performed for the thickness and work function variations of MgF2 layers.
Metallic Layers on Graphene based Paper Electrodes for Better Energy Storage Characteristics
(Library Information Services, COMSATS University Islamabad, Lahore Campus, 2021) Iqra Manzoor; CIIT/SP19-RPH-030/LHR; Dr. Ishrat Sultana; LHR TP 7254
This research aspires to have an unconventional and alternative source for flexible and bendable energy storage devices that have proved very useful to meet the demand of today’s energy crises. It is very interesting to use natural self-growing plant’s lignocellulose that are very abundant on earth and convert them in the form of paper-based electrodes. Fibers from Monochorea Vaginalis plant were taken and then dried, which were then treated in a solution to make flexible and smooth sheet. Scanning electron microscopy results presents the information about the surface morphology of naked sample, coated sample as well as composite with LC fibers. Addition of LC fiber makes the working electrode flexible, low cost and environmentally friendly for flexible energy storage applications. Poor conductivity of LC/graphene oxide based flexible sheets were addresses by the electrodeposition of metallic nanoparticles (i.e., Ni) on fabricated sheets (LC/graphene oxide). Electrochemical cyclic voltammetry measurements were performed. These fabricated composites can be used further as flexible electrodes in energy storage applications because of enhanced electrochemical properties.
Optical and Electrochemical properties of MoS2 Based Doped Nanostructures for Renewable Energy Devices
(Library Information Services, COMSATS University Islamabad, Lahore Campus, 2021) Imtisaal Hussain; CUI/SP20-RPH-062/LHR; Dr. Ishrat Sultana; LHR TP 7703
To address the increasing energy demand at global level, renewable energy resources are the promising alternative of the hazardous fossil fuels and petroleum products which are also expected to run out in future. Renewable energy resources include thin film solar cells, fuel cells, supercapacitors, and batteries. Among these resources, thin film solar cells are considered to be an efficient energy resource due to abundant sunlight available in various parts of the earth. Solar cells convert sunlight to electrical power and therefore considered to be highly cost effective and can be manifested into flexible solar panels for a convenient installation and energy harvesting through electrochemical mechanism present within the cells. However, charge losses within the device owing to various factors limit the performance of these next generation devices and prevents them to set footing at commercial level. Many aspects of the device structure including working electrode, electrolyte and counter electrode play a crucial role in dictating the device performance. Among these components, counter electrode (CE) is of primary importance which acts as a catalytic agent for charge collection from the external circuit and provide it back to the working electrode for regeneration of the light absorber material coated on the working electrode. This, in return provides charges to the external circuit after absorbing suitable wavelength from the solar spectrum. The CE must have large surface area to provide more electroactive sites for charge transfer, efficient catalytic behavior to facilitate oxidation- reduction process in the cell, should be chemically stable, cost effective and environment friendly. This would prevent charge losses thus improving device efficiency. Molybdenum sulfide (MoS2) is a recently investigated 2-D material which has graphene like structure as well as efficient charge conducting properties. This material is widely employed in CE applications in thin film solar cells as it offers wide variety of possibilities to design a CE material which will exhibit all above mentioned merits.. However, due to inherent multi stacking of S-Mo-S layers, some of the electroactive sites are blocked which inhibit performance of the CE. This can be circumvented by synthesizing novel MoS2 nanocomposites and metal atom adsorption. Since the phenomenon dictating the availability of maximum electroactive sites for charge transfer, and chemical stability still needs to be fully understood, this necessitates developing new MoS2 based nanocomposites via ad-atoms and investigating their performance in CE based applications for thin film solar cells. In this work, metal doped MoS2 nanostructures is synthesized via facile wet chemical routes and studied as CE materials in prototype PV devices. The structural, morphological and electrochemical performance of the structures is analyzed by using Raman, PL and UV-Vis, and EIS characterization techniques.
Synthesis and Characterization of Nickel doped Zinc Oxide Based Paper Electrode for Dye- Sensitized Solar Cells
(Library Information Services, COMSATS University Islamabad, Lahore Campus, 2024) Maria Ejaz; CIIT/SP23-RPH-027/LHR; Dr. Ishrat Sultana; LHR TP 9644
Flexible dye-sensitized solar cells (DSSCs) are a desirable alternative to rigid glass substrate-based solar cells because of the potential for flexibility and light weight. Researchers and scientists have been fascinated by polymer based electrodes due to its durability and flexibility. However, the production of polymers requires the use of hazardous chemicals. As a result, the tendency has shifted toward material synthesis methods that are safer, more affordable, and more sustainable. A flexible working electrode composite based on nickel (Ni) doped zinc oxide (ZnO) is synthesized in this project, by adding lignocellulose (LC) fibers. It is an effort to expand the potential of flexible electrodes based on metal oxide for DSSC applications. The co-precipitation process is used to create a transition metal-doped nanostructure (Ni doped ZnO). Doped particles with regulated composition, size, and homogeneity can be easily prepared at room temperature using this synthesis method. As a result, this work uses natural fibers to give Ni- doped ZnO a compact and porous structure for energy conversion applications. More sunlight will be absorbed as a result of the increased porosity, increasing the DSSC cell’s efficiency.
Synthesis and Simulation of Metal Oxide based Nanostructures for Thin-Film Solar Cell Applications
(Library Information Services, COMSATS University Islamabad, Lahore Campus, 2020) Muqaddas Akram; CIIT/FA18-RPH-035/LHR; Dr. Ishrat Sultana; LHR TP 6091
In this work, we employed a solution-based hydrothermal process to synthesize the Zinc Oxide (ZnO) nanorods on a coated glass substrate. For the growth process, metal oxide with a thickness <300 was used as a seed layer for further growth of nanostructures. The glass substrate coated with metal oxide was then immersed in the precursor solution, then a hydrothermal process was performed at 90 ° C using different types of growth hours. The length and diameter of ZnO nanorods were controlled by varying the growth time, the concentration of the precursor solution and the temperature etc. Scanning electron microscope (SEM) images were used to determine the surface morphology of metal Nano-oxide rods. Characterization of the optical transmission (full and diffuse) was performed using a UV-Vis spectrophotometer. In addition, the photovoltaic device was simulated using (ZnO) and amorphous silicon layers (p, i, n) from thin film solar cell (TFSC) functions.
Synthesis of Biochar and Metal Based Working Electrode for Dye Sensitizer Solar Cell Application
(Library Information Services, COMSATS University Islamabad, Lahore Campus, 2025) Memoona Zahoor; SP23-RPH-001; Dr. Ishrat Sultana; LHR TP 9624
Banana peels are used as a preceding material in this investigation. It is dried, converted to bio Char, and then activated to generate activated carbon. Together with iron oxide, these components activated carbon powdered banana peel, and bio Char form a composite structure that aims to enhance the DSSC electrodes electro chemical characteristics. Because of its enormous surface area, porosity and conductivity, bio Char is a great substrate for introducing iron oxide nano particles. This improves DSSC stability and photo current production. According to the findings, the bio Char /iron oxide composite electrodes outperform pure bio Char and activated carbon electrodes in terms of power conversion efficiency and long-term stability. Through the efficient energy conversion of waste-derived materials for renewable energy technologies, this work presents a viable and cost-effective method for creating DSSC electrodes. Scanning electron microscopy (SEM) and x-ray diffraction (XRD) are two material approaches that have been used to assess the electrodes structural or morphological properties. The different functional groups contained in the produced electrodes have been identified using Fourier transform infrared spectroscopy (FTIR). The band gap is determined via UV-Vis spectroscopy through a Tauc plate. J-V plots and efficiency calculations are provided by the solar simulator.
Synthesis, Characterization and Photocatalytic Performance of Modified Ag doped SnO2/ ZnO Nanocomposites
(Library Information Services, COMSATS University Islamabad, Lahore Campus, 2021) Raja Zulqarnen; CIIT/SP20-RPH-007/LHR; Dr. Ishrat Sultana; LHR TP 7682
Photo catalysis is low cost and environment friendly process for cleaning the water and removing organic pollutant. In our work, we employed a co-precipitation method to synthesize the silver doped tin oxide/Zinc Oxide Nano composites. This catalyst absorbs UV energy and in aqueous medium it degrades methylene blue dye. Scanning electron microscope (SEM) images were used to determine the surface morphology of Ag doped SnO2/ZnO. Characterization of the optical transmission (total and diffuse) was performed using FTIR analysis. XRD analysis was performed to determine the crystal structure. Raman analysis was used for the chemical structure of the NCs. In addition, photo catalytic activities were performed with the help of photo catalytic reactor chamber and UV spectroscopy for the degradation of the MB dyes.